Tilting Wheeled Vehicle

ABSTRACT

A tilting, preferably three-wheeled, vehicle is disclosed that has a tilting mechanism and a universal steering linkage that allows the vehicle to have leaning and steering characteristics substantially similar to those offered by an in-line two-wheeled vehicle, but that does not require complex linkages and/or control systems to operate effectively. A tilting linkage is operably secured to a frame to allow a pair of spaced apart wheels to remain substantially aligned with the plane of the vehicle throughout its range of movement while still providing an increasing camber between the wheels as tiling of the vehicle increases. A tilting lock system may be provide to limit tilting of the vehicle upon predetermined criteria.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Application No.14/589,734 filed Jan. 5, 2015, which is a continuation of U.S.Application No. 13/460,282, filed Apr. 30, 2012; which is a continuationof U.S. Application No. 13/235,344. filed Sep. 16, 2011; which claimsthe benefit of U.S. Provisional Application No. 61/838,636, filed onSep. 16, 2010, all of the disclosures of which are hereby incorporatedby reference. This application also claims priority to U.S. ProvisionalPat. applications Nos. 62/239,898; 62/239,900; and 62/239,905, all filedon October 10. 2015, and all the disclosures of which are herebyincorporated by reference.

FIELD OF THE INVENTION

This invention relates to wheeled vehicles such as motorcycles and thelike. More particularly, this invention relates to a stable, preferablethree-wheeled vehicle that offers maneuverability characteristics thatare substantially similar to those of an in-line, two-wheeled vehicle.

BACKGROUND OF THE INVENTION

Unlike a typical three and four wheeled vehicles, in-line, two-wheeledvehicles, such as motorcycles, bicycles, and the like, allow a rider tolean or tilt while turning without urging the rider toward the outsideof the turn. Instead, the rider of the in-line two-wheeled vehicle ispushed straight down into the seat as the free leaning motorcyclebalances the vertical gravity vector with the horizontal vector createdby going around a corner. The faster the rider goes around a corner, themore the In-line two-wheeled vehicle needs to lean.

But two-wheeled in-line vehicles are limited by only having one fronttire as well as having the rider sitting high on the vehicle. The onefront tire limits the amount of braking and amount of traction that canbe achieved.

Efforts to apply tilting characteristics to three and four-wheeledvehicles have had limited success. Examples of such vehicles and theirlimitations are discussed In greater detail in an article titled “SomeTechnical Aspects of Tilting Trikes,” by Tony Foale, B. Tech, M.Eng.Sc.dated Mar. 21, 1999, the disclosure of which is hereby incorporated byreference.

In general, these known tilting three-wheeled vehicles are limited bynot allowing proper tilt of the vehicle, complex tilting structures thatrequire excessive user interaction, and/or requiring complexcontrolsystems to operate effectively.

SUMMARY OF THE INVENTION

Despite the available three-wheeled vehicles, there remains a need for athree-wheeled vehicle that allows leaning and steering substantiallysimilar to that offered by an In-line two-wheeled vehicle, but that doesnot require complex linkages and/or control systems to operateeffectively. In addition to other benefits that will become apparent inthe following disclosure, the present invention fulfills these needs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear, right, isometric view of a tilting three-wheeledvehicle in accordance with an embodiment of the present invention.

FIG. 2A Is a front, plan view of the tilting three-wheeled vehicle ofFIG. 1 showing a possible straight position of the vehicle and the frontwheels aligned to urge the vehicle In a straight direction.

FIG. 2B is a front, plan view of the tilting three-wheeled vehicle ofFIG. 1 showing a possible leaning position of the vehicle with the frontwheels aligned to urge the vehicle in a straight direction

FIG. 3 is a front, plan view of the tilting three-wheeled vehicle ofFIG. 1 showing a possible leaning position of the vehicle and the frontwheels turned to define a possible right turn.

FIG. 4 is a partial, enlarged, isometric view of the right wheelassembly of the tilting three-wheeled vehicle of FIG. 1 .

FIG. 5 is a front, isometric view of an alternative linkage for use on atilting three-wheeled vehicle in accordance with an embodiment of thepresent invention.

FIG. 6 is a left, isometric view of the alternative linkage of FIG. 5showing a possible orientation on a motorcycle chassis shown in brokenlines.

FIG. 7 is a schematic diagram of a possible tilt-locking control logicin accordance with an embodiment of the present Invention.

FIG. 8 is a partial top, right isometric view of the front end of atilting three-wheeled vehicle in accordance with alternative embodimentof the present invention.

FIG. 9 is a front view of the tilting three-wheeled vehicle of FIG. 8 .

FIG. 10 is a bottom view of the tilting three-wheeled vehicle of FIG. 8

FIG. 11 is a partial front view of the tilting three-wheeled vehicle ofFIG. 8 showing a possible tilted position of the vehicle.

FIG. 12 Is a top view of the tilting three-wheeled vehicle of FIG. 8 .

FIG. 13 Is an enlarged, isometric view of a steering system universaljoint installed on the tilting three-wheeled vehicle of FIG. 8 and inaccordance with an embodiment of the present invention.

FIG. 14 is an exploded, isometric view of the steering system universaljoint of FIG. 13 .

FIG. 15 is a rear, right isometric view of the three-wheeled vehicle ofFIG. 8 .

FIG. 16 is a front view of the three-wheeled vehicle of FIG. 8 showing apossible tilted position of the vehicle.

FIG. 17 is a front, right view of the three-wheeled vehicle of FIG. 8showing a possible fender and front end cover arrangement.

FIG. 18 is a front, left isometric view of the three-wheeled vehicle ofFIG. 8 showing a possible hydraulic disk tilt lock structure.

FIG. 19 is an exploded for of an alternative possible universal joint inaccordance with an embodiment of the invention.

FIG. 20 is an enlarged partial isometric view of the alternativeembodiment steering system incorporating the universal joint if FIG. 19.

FIGS. 21 A-C s a flow chart of a possible tilt lock control logic inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A tilting three-wheeled vehicle 10 with an improved pivoting pair ofspaced-apart steering wheels 12 a, 12 b operably secured thereto with atilting linkage 14 extending between the steering wheels 12 a, 12 b andthe vehicle 10 is disclosed in FIG. 1–21C. A first preferred tiltinglinkage 14 is shown in FIGS. 1-4 , and a second preferred tiltinglinkage 14' Is shown in FIGS. 5 & 6 , and a third preferred linkage withoptimized suspension is shown in FIGS. 8-18 . In addition, a preferredtilting lock mechanism (FIG. 18 ) and related control logic (FIGS. 7 &21A-C) is disclosed, and a steering yoke that allows the wheels to besteered throughout the complete tilting range of motion of the vehicleis disclosed In FIGS. 13-15 & 19-20 . The disclosure embodiments alsoallows the caber between the left and right wheels of the tiltingvehicle to proportionally increase as the vehicle leans, therebyoptimizing stability, control, and the feel of the vehicle. Each ofthese embodiments and features is discussed in greater detail belowand/or in the materials incorporated by reference.

Referring to FIGS. 1-4 , the vehicle 10 replaces the front wheel of atwo-wheeled in-line vehicle with a the pair of substantiallyparallel-aligned wheels 12 a, 12 b joined to the vehicle 10 by a linkage14 that tilts each wheel 12 a, 12 b substantially similar to the tilt ofthe vehicle 10 during use.

In one disclosed embodiment best shown in FIG. 2A, the linkage 14 has anupper and lower spaced-apart and substantially elongate cross members20. 22, respectively, that are each pivotally secured to the front ofthe vehicle at respective pivots 24, 26. The upper and lower spacedapart cross-members 20, 22, are substantially parallelly aligned, withthe pivots 24, 26 for each cross-member being substantially aligned onthe steering axis 30 of the vehicle 10.

Auxiliary steering shafts 32, 34, which are also referred to as•“kingpins” herein, are operably secured to the distal ends of eachrespective cross member defining a left steering shaft 32 extendingbetween the left distal ends 40 of the upper and lower cross-members 20,22 and a right steering shaft 34 extending between the right distal ends42 of the upper and lower cross-members 20, 22. The left and rightsteering shafts 32, 34 are substantially parallelly aligned with eachother and the steering axis 30 of the vehicle and have substantially thesame caster angle 50 (FIG. 4 ).

In one embodiment, the king pins preferably do not go through the centerof their respective wheel axis but rather are set back toward the rearof the vehicle approximately 2.5 inches to allow the contact patch ofthe tire to be slightly behind an imaginary line that goes down thecenter of the king pin. Alternatively, no offset need be provided solong as each wheel’s caster angle 50 (FIG. 4 ) Is adjusted accordingly.

Each wheel 12 a, 12 b of the pair of wheels 12 Is operably secured toone of the steering shafts 32, 34. The left wheel 12 b is operablysecured to the left sheering shaft 32 and the right wheel 12 a isoperably secured to the right steering shaft 34 so as to allow eachwheel 12 a, 12 b to turn about its respective steering axis B, C.Accordingly, the steering axes B & C of the left and right wheel 12 a,12 b are substantially parallelly aligned with the steering axis 30 ofthe vehicle 20 and each wheel 12 a, 12 b is able to turn about itsrespective steering shaft 32, 34. More preferably, each steering shaft32, 34 is aligned so that its respective steering axis B, C iscoincident with a substantially vertical plane 200, 202 intersecting thelongitudinal center 204. 206 of the respective wheel as best shown inFIG. 2A.

Preferably, the handlebars 60 of the vehicle 10 operably engage aprimary steering shaft 62 (FIG. 3 ), which defines the steering axis 30of the vehicle. A first tie rod 64 extends from a lower portion of thesteering shaft 62 to the right wheel 12 a, and a second tie rod 66extends from the right wheel 12 a to the left wheel 12 b as shown.Accordingly, when a rider turns the handlebars 60, the steering shaft 62rotates in the commanded direction thereby urging the first tie rod 64to turn the right wheel 12 a about the right steering shaft 34. Thesecond tie rod 66 simultaneously urges the left wheel 12 b to pivot inthe same commanded direction about the left steering shaft 32.Accordingly, it can be appreciated that the vehicle may be steered insubstantially the same manner as a conventional in-line two-wheeledvehicle.

Preferably and referring to FIGS. 2A & 4 , a suspension system 70, suchas a spring 72 and/or dampener 71, operably engage each wheel 12 a, 12 bas shown. An alternative preferred linkage system with suspension system70' is shown in FIGS. 14-30 . An upper pivot frame 24 and lower pivotframe 26 are aligned along the steering axis 30 of the vehicle. Crossmembers 20 a, 20 b, 22 a, 22 b, extend from the upper and lower pivotframes to their respective wheels 12 a, 12 b as shown. A lowersuspension frame is pivotally secured to the lower pivot frame and aC-shaped suspension support straddles the upper pivot frame and ispivotally secured to the lower suspension support. Suspension elements,such as a spring and/or dampener extend from the C-shaped suspensionsupport to suspension mounts at each wheel 12 a, 12 b. Accordingly, thesuspension elements remain in their neutral positions throughout thetilting and turning range of motion of the vehicle as best shown InFIGS. 28, 3, 11, and 16 .

More preferably, the steering system components are configured so as toprovide conventional Ackermann steering. Referring to FIGS. 13-15 auniversal joint steering yoke 250 operably connecting a steering shaft62 (FIG. 15 ) to the wheels (12 a, 12 b) with tie rods (64 a, 64 b).This joint allows each front wheel to be steered by the handlebarwithout compromising steenng feel or force on the rider throughout theentire tilting range of motion of the vehicle.

Alternatively, a universal joint as shown in FIGS. 19 & 20 may be used.A discussion of its assembly, use and operation is provided inAttachment A to U.S. Provisional Pat. Application No. 62/239,898, filedOct. 10, 2015, the disclosure of which is hereby incorporated byreference. The following coordinate system facilitates this discussion.Axis X is defined down the centerline of threaded rod as well as downthe centerline of Aurora AM-8T Rod End. Axis Y is defined down thecenterline of bearing through pinch washer, and Axis Z is defined downthe centerline of button head bolt and 0.875 bearing.

The threaded rod is attached to the proximal end the right steering tierod. Right being defined as the rider’s right when seated on the bike.The distal end of the right steering rod is connected to the right wheelhub assembly. The Aurora AM-8T Rod End is attached to the proximal endof the left steering tie rod. The distal end of the left steering tierod is connected to the left wheel hub assembly. A bolt is goes throughbearing and connects the whole steering joint to a steering knuckle.

The steering joint allows both the left and right tie rods toindependently pivot about both the Z & Y axes. The tie rods pivot aboutthe Y-axis to allow for suspension travel. The tie rods pivot about theZ-axis to allow for steering. At the same time, the whole joint is ableto pivot about the Y axis to allow for the vehicle to lean while notaffecting either the steering or the suspension travel. With the tierods positioned as shown in the FIG. 20 , when the steering is turned tothe left, the left tie rod travels a shorter distance than the right tierod because is traveling through a shorter arc. This causes the leftwheel to turn less than the right wheel. This is the opposite steeringeffect desired when you are trying to achieve the proper Ackermann’ssteering which wants the inside wheel (left in this case) to turn morethan the outside wheel (right in this case). Our knuckle keeps thosedistances the same and allows you to achieve proper Ackermann’s geometryby the positioning of the distal tie rod end on the spindle housing.

With the tie rods positioned as shown in the FIG. 20 , when the steeringis turned to the left, the left tie rod travels a shorter distance thanthe right tie rod because is traveling through a shorter arc. Thiscauses the left wheel to turn less than the right wheel. This is theopposite steering effect desired when you are trying to achieve theproper Ackermann’s steering which wants the inside wheel (left in thiscase) to turn more than the outside wheel (right in this case). Ourknuckle keeps those distances the same and allows you to achieve properAckermann’s geometry by the positioning of the distal tie rod end on thespindle housing.

The steering joint also allows for almost zero bump steer with ourtilting front end geometry since the tie rod is pivoting about the samecentral axis as the upper and lower a-arms.

This steering knuckle may also be used in a slightly differentconfiguration as a joint similar to a U-joint but allow for a higherangle of power transfer. The power in could be one side of the Axis X(like the threaded rod in our example) and the power out would be theopposite side of Axis X (like the Aurora AM-8T Rod End (7) in ourexample). The axes Y and Z would be unconstrained.

The present invention allows a three-wheeled vehicle to leansubstantially similarly to an in-line two-wheeled vehicle. Referring toFIGS. 2A, 28 and 3 , when the steering axis 30 of the vehicle is alignedsubstantially vertically as shown in FIG. 2A, both the left wheel 12 band right wheel 12 a are aligned substantially vertically. However,during turning operations, such as a right turn shown in FIG. 3 , whenthe vehicle naturally leans into the turn, the left and right wheelsalso lean by substantially the same amount. Referring to FIG. 28 , alean to the right will also cause the left and right wheels to leanright by substantially the same amount.

Referring to FIGS. 5 & 6 , an alternative preferred tilting linkage 14'is disclosed. In order to reduce undue repetitio,. like elements betweenthis embodiment and the previously disclosed tilting linkage 14 are likenumbered.

The alternative preferred linkage 14' of FIGS. 5 & 6 preferably has apair of upper cross members 20 a, 20 b and a vertically spaced apartpair of lower cross members 22 a, 22 b respectively. Each cross member20 a, 20 b, 22 a, 22 c is pivotally secured to the front of the vehicleat respective, substantially horizontal, pivot shafts 24', 26'. Namely,cross members 20 a, 20 b are pivotally secured to pivot shaft 24' andlower cross members 22 a, 22 b are pivotally secured to pivot shaft 26'.The pivot shafts 24', 26' are positioned substantially vertically withrespect to each other along the steering axis 30 and spaced apart fromeach other as best shown in FIG. 5 . Accordingly, the distal ends ofupper cross member 20 a and lower cross member 22 a move substantiallyIn the directions of arrow 100 and the distal ends of upper cross member20 b and lower cross member 22 b move substantially in the directions ofarrows 102 as the steering shaft tilts about arrow 104.

Auxiliary steering shafts 32, 34. which are also referred to as“kingpins” herein, are operably secured to the distal ends of eachrespective cross member defining a left steering shaft 32 extendingbetween the left distal ends 40 of the upper and lower cross-members 20b, 22 b and a right steering shaft 34 extending between the distal ends40 of the upper and lower cross-members 20 a, 22 a. The left and rightsteering shafts 32, 34 are substantially parallelly aligned with eachother.

If desired, the caster angle 50 (FIG. 4 ) of the left and right steeringshafts 32, 34 can differ from the caster angle of the steering axis 30.More preferably, the castor angle 50 of the left and right steeringshafts 32, 34 Is selected so that there is about a 2.5 inch to 3.5 inchtrail, defined as the distant between the contact patch of therespective wheel 12 a, 12 b with the ground and the contact point withthe ground of an imaginary line extending from the respective steeringshaft 32, 34. More preferably, the trail for each wheel 12 a. 12 b isabout 3 inches. It can be appreciated that since the steenng axis 30 Isseparate from the kingpins, any steering axis angle may be used tooptimize driver handlebar positioning while still allowing for theoptimizing each wheel’s caster angle.

Each wheel 12 a, 12 b of the pair of wheels 12 is operably secured toone of the steering shafts 32, 34. The left wheel 12 b is operablysecured to the left sheering shaft 32 and the right wheel 12 a isoperably secured to the right steering shaft 34 so as to allow eachwheel 12 a, 12 b to turn about Its respective steering axis B, C.Accordingly, the planes of the left and right wheel 12 a, 12 b aresubstantially parallelly aligned with the steering axis 30 of thevehicle 20 and each wheel 12 a, 12 b is able to turn about itsrespective steering shaft 32, 34.

Preferably, the handlebars 60 of the vehicle 10 operably engage aprimary steering shaft 62 (FIG. 5 ), which defines the steering axis 30of the vehicle. A first tie rod 64 a extends from a lower portion of thesteering shaft 62 to operably engage the right wheel 12 a, and a secondtie rod 64 b extends from the lower portion of the steering shaft 62 tooperably engage the left wheel 12 b as shown. Accordingly, when a riderturns the handlebars 60, the steering shaft 62 rotates in the commandeddirection thereby urging the first tie rods 64 a, 64 b to turn theirrespective wheels in the commanded direction. Accordingly, it can beappreciated that the vehicle may be steered in substantially the samemanner as a conventional in-line two-wheeled vehicle.

Preferably and referring to FIGS. 5 & 6 , a suspension system 70', suchas a spring 120 and/or dampener 122, operably engages the linkage 14'.More preferably, the spring 120 and dampener 123 are pivotally securedto both the left and right portions of the linkage 14' at pivots 114,112, respectively as shown. Accordingly, both the left and rightportions of the linkage 14' are independently movable in the directionsof arrows 102, 100, respectively, while also being urged to a neutral,substantially horizontal configuration with respect to each other.

More preferably, the tie bars 64, 66 are sized to as to allow the outerwheel in a given turn to turn slightly less in the commanded directionthan the inner wheel of the turn.

Referring to FIGS. 8-12 and 15 and 16 , an alternative linkage structureproviding constant dampening suspension force throughout the entiretilting range of motion of the vehicle is shown. A c-shaped memberstraddles the vehicle frame and operably connects left and rightsuspension elements 210 to the wheels 12 a, 12 b. This orientationallows the force on the suspension elements 210 to remain constant whenthe vehicle is tilted as shown in FIG. 16 or standing straight up asshown in FIG. 9 , and with the wheels 12 a, 12 b turned as shown in FIG.18 or pointing straight as shown in FIG. 9 .

The disclosed embodiments allow positioning of a driver low in thevehicle 10 behind the engine. Preferably, placing the engine to the rearwould create a vehicle too light In the front where most of the brakingoccurs and would can make the vehicle prone to oversteering issues whichwould lead to spin outs. Placing the motor in the front would mostlikely lead to an understeering vehicle, which would be a safersituation when driving at the vehicle’s limits. Lowering of thevehicle’s center of gravity Is universally seen as desirable and reducesthe chance of the vehicle flipping over which is very difficult to do ona motorcycle or like vehicle unless the wheels encounter somenon-movable object such as a curb or rock. This characteristic is knownby motorcyclists as “highsiding” and tends to sling the rider up overthe top of their bike. Lowering the vehicle’s center of gravity willallow the vehicle to shift from a left to right turn faster than asimilar vehicle with a higher center of gravity.

This three-wheeled vehicle 10 of the present invention allows it tosteer and maneuver like a conventional h-line two-wheeled vehicle buthave better braking and traction capabilities. With the driver sittinglow in the vehicle like In a sports car, he would not have theuncomfortable feeling of being tossed left or right when cornering hard.

There are two ways to achieve a leaning vehicle. One way is to have thevehicle “free lean” such as a motorcycle where the steering input is theonly force needed to create the lean. A free leaning vehicle needs to beable to lean at up to a 45-50 degree angle to allow for a maximum leanrequired during a fast tight turn. If the free leaning vehicle ismechanically challenged in that it cannot achieve such a lean withoutpart of the chassis hitting the pavement or some binding occurring inthe leaning mechanism, then the forces are not adequately balanced andthe driver begins to feel the force of being toss to the outside. Thisalso causes the force on the tires to no longer be straight down and cancause the vehicle to slide as motorcycles do not have much of a contactpatch on the pavement and are not designed to handle side load forces.

The other way to achieve a leaning vehicle relies on complex controlsystems such as computer input from steering sensors to commandhydraulic actuators as needed to force the vehicle to lean.

The present invention relies on a free leaning design. It has beendesigned to have no clearance Issues up to 45 degrees so it should beable to lean up to all angles required by the driver regardless of speedor sharpness of turn. It will steer like a motorcycle and require use ofcounter steering to control. This method of steering is familiar to allmotorcyclists who are able to switch back and forth between steering acar and a motorcycle with no confusion. Anyone truly wanting to learn todrive a motorcycle is not put off by the fact that it steers differentlythan a car. In fact, many motorcyclists do not even realize that theyare using counter steering to control their bike and just do itintuitively. People who have not driven motorcycles before may find thevehicle difficult to control until they learn how to steer it properly.

The preferred embodiment of the present invention is also far lessexpensive and complicated to manufacture than any forced leaningvehicle.

With Increased up front traction and braking capabilities of amotorcycle combined with a lower center of gravity than a motorcycleoffered by at least one embodiment of the present Invention, the vehicleof the present invention will outperform motorcycles with the same sizeengine despite being slightly heavier due to the additional steeringlinkage and additional wheel.

Known tilting vehicles mislocate the kingpins which are offset towardthe center of the vehicle similar to how an automobile’s steering isbuilt. By centering the kingpin left to right inside the wheel of amotorcycle type tire and rim and bringing the kingpin inclination angle(or known as Steering Inclination angle (SIA) or Steering AxisInclination (SAI)) to 0 degrees, the present invention achieves asubstantially 0 scrub radius when the vehicle is tracking In a straightline which is substantially similar to how a motorcycle’s steeringworks. The scrub radius will then shift from positive to negative as thevehicle leans with one side being positive and the other being negativeat the same lean angle.

The castor of the kingpins can also mimic that of a motorcycle and be inthe range of 24-30 degrees. Sport motorcycles have a smaller castorangle while “choppers” have a lot more. The first disclosed embodimenthas a middle of the range 27 degrees. The second disclosed embodimenthas a preferred castor angle of about 15 degrees. Of course, othercaster angles could be used depending on a particular application.

The camber is preferably set up to be slightly positive. Accordingly,the inside tire preferably leans slightly more since It Is following asmaller radius. While traveling straight ahead, both tires will want topull slightly to the outside but their forces should offset each other.At slower speeds (i.e. 1-5 mph), the rider will turn the steering to theright In order to turn the vehicle right. At speeds higher than that theeffect of counter steering kicks in and the rider must turn the steeringto the left in order for the vehicle to go to the right.

More preferably, the linkages and their related mounting locations tothe frame and left and right wheels are positioned so as to allow thecamber between the left and right wheels to increase proportionally tothe amount of tilt of the vehicle. This concept is discussed more fullyin U.S. Provisional Pat. Application No. 62/239,905, filed on October10. 2015, the disclosure of which is hereby incorporated by reference.

The base concept of this proportionally increasing camber concept issimilar to how Ackermann’s steering works to give the proper steeringangle to the two front wheels of a vehicle that always stay straight upand down. In addition to following Ackermann’s steering principles,proportionally increasing the camber allows for proper lean angles sothat the two wheels in the front of a vehicle achieve proper leaningangles while going around a corner.

Tilting vehicles need something similar to Ackerman’s steering principleto allow the inside wheel to lean at more of an angle as the vehicleleans while going around a corner. A vehicle with a two wheeled tiltingfront end does not steer around a corner but actually turns by leaningand riding on the smaller radius of the curved tires diameter. As thevehicle goes down the road in a straight line, it is ideal to have thetwo front wheels parallel. The wheels will have 0 toe and 0 camber asthe vehicle corners, it is ideal to have the inside wheel lean at moreof an angle as it is following a tighter corner radius as compared tothe outside wheel. Again, very similar to Ackerman’s steering butapplied to a leaning vehicle. In our example shown below on our tiltingthree wheeler, at 0 degree lean angle, Y is 0". At 45 degrees of leanangle, Y may be 0.25". X is approximately 36". The proper set-up allowsY to increase slightly as the vehicle leans. In other words, thegeometry allows the camber to proportionally increase as the vehicleleans. If you do not have the correct geometries set to allow thisdifference, the wheels will scrub and cause premature wear on the tires.By allowing the tires to follow the natural lines that they want tofollow, the tires wear evenly. The correct geometry is achieved by usingour soon to be patented steering joint and positioning the tie rods inthe appropriate position on our hubs located on the centerline of thewheel. By properly joining the tie rods to the hubs, the vehicle canachieve proper Ackermann’s steering at slow speeds when the wheels arenot leaned over and the proper geometry that allows the inside wheel tolean more than the outside wheel at speed. The variable geometry is alsoachieved by having the hubs leaned back slightly (defined as “rake”below) which gives the proper trail (see diagram below) to the frontwheels.

Currently, unless supported by the driver’s feet or by a kickstand, thevehicle 10 of the present invention remains free-leaning, like amotorcycle Accordingly, it will tend to tilt sideways when operating atvery slow speeds, when stopped, and when parked. Accordingly, it canfall-over, just like a motorcycle: unless supported by the rider or akickstand.

If desired, the vehicle can be configured to reduce or eliminate freeleaning when stopped or operated at slow speeds. For example, the frontof the vehicle can be temporarily and automatically locked at acommanded, straight position at slow speeds and when stopped with nopivoting allowed along pivots 24 and 26. An exemplar control logic foractivation of the tilting lock is shown schematically in FIG. 7 .

Alternative possible control logic configurations are shownschematically in FIGS. 21A-21C and shown and discussed in U.S.Provisional Pat. Application No. 62/239,900 filed on Oct. 10, 2015, thedisclosure of which is hereby incorporated by reference.

The Tilt Lock system is designed to lock the bike so that it doesn’tlean at low speeds or when stopped and will bring the bike vertical ifoff centered. Once the bike starts to accelerate or gets above a certainspeed the lock will release and allow the bike to lean freely. Riderscan enjoy the handling of a 2-wheeled motorcycle without having tosupport the bike when stopped.

There is a low speed setting (around 1 mph) where this system is alwayslocked and there is a high speed setting (around 7 mph) where the systemis always off. Between the high speed and low speed setting, the systemis either locked or unlocked depending if the bike is accelerating ordeaccelerating.

Once the bike is locked, the program goes into a looping program sensingwhether the bike is level or not to the horizon, if it is not level, itactivates the hydraulic motor which drives the hydraulic cylinders tolevel the bike. This happens continuously until the system is unlocked.Leveling the bike perpendicular to the horizon rather than perpendicularto the road surface is the natural state the rider wants to be in.

If the handle bars are turned sharp enough beyond a certain setting, thesystem will always stay locked up to the high speed setting. This allowsthe rider to make sharp U-turns at less than the high speed settingwithout having to worry about the bike unlocking.

When the bike is less than 1 mph (or so) steering input will slightlylean the bike. At a stop, or less than Y, if you turn your handlebars tothe right, the bike will slightly lean to the right. This functionpreleans the bike to assist the rider in making an immediate turn to theright or left from a stop. The more you turn the handlebars, the morethe bike is leaned over. The proportion of the turning to the lean canbe fixed or variable. If you don’t have this function and the bike islocked vertical, and you make an immediate hard right turn and thesystem switches from locked to unlock, it will cause the bike to bethrown to the outside of the corner and is very disconcerting to therider. By having the bike preleaned, the bike and rider follow thenatural leaning path the bike wants to take.

Exemplar General System and Environmental Requirements

-   1) Operating voltage 12 V +/--   2) Operating temperature: -30◦ to +150° F.-   3) Board protected against overload, short-circuit, reverse polarity    and power surge-   4) Dual board design for redundancy.-   5) Will need to be robust enough to handle extreme vibration and wet    weather conditions

Inputs

-   1) Inputs for two quadrature sensors Honeywell X209356-GT (see    attached spec sheet for SNG-Q sensors)-   2) On-board accelerometer for tilt sensing (looking at using    attached Bosch units)-   3) May use same or separate accelerometer for Acceleration and    Deceleration measurements-   4) One 0-5 V input for the Honeywell RTY120HVNAX sensor for steering    (see attached RTY spec sheet)-   5) On/off switch

Outputs

-   1) One solenoid output max 1.5 A (see attached spec for Sun Coil)-   2) Output for one motor, reversible, max 20 A driving hydraulic    pump. Currently using Parker Oildyne 118AES10-ALL-1V-20-20 unit with    two wire motor, could look at 118AMS10-ALL-1V-20-20 unit with three    wire motor. See attached spec for Parker Hydraulic Unit-   3) Error indicator bulb or display (need to determine fault state)-   4) Indicator showing bike is stopped and solenoid is activated

Such control systems for detecting speed and activating a controller tolimit movement are known. For example, the speed control could beactivated by a connection to a traditional speedometer measuring therotation of the wheel since the vehicle would Jock up anytime the brakeswere applied hard enough to lock up the wheels. Alternatively, vehiclespeed can be monitored, by an on- board GPS system, a radar system, aradio frequency transmission system or the like that would measure thevehicle’s true speed and apply a mechanical lock 300 (FIG. 18 ) once thespeed of the vehicle reaches less than say 3 mph. An exemplar mechanicallock 300 featuring a hydraulic brake 302 operably secured between thevehicle frame and the lilting linkage is shown in FIG. 18 . With such asystem installed, the driver would not have to put his or her feet onthe ground once the vehicle came to a stop.

Moreover, the tilting linkage 14 and 14' can include a frame portion 130adapted to fit onto the front end of a conventional in-line two-wheeledvehicle such as a conventional motor cycle or the like. Such frame wouldinclude conventional fittings and the like to allow the steering shaft30 to connect to the existing handlebar system of the conventionalin-line two-wheeled vehicle.

In view of the wide variety of embodiments to which the principles ofthe invention can be applied, it should be apparent that the detailedembodiments are illustrative only and should not be taken as limitingthe scope of the invention. For example, although the disclosedembodiment positions the pair of wheels 12 a, 12 b on the front of thevehicle, the principles of this invention would also work with the pairof wheels 12 a, 12 b replacing the rear wheel of an in-line two- wheeledvehicle. Similarly, a four-wheeled vehicle with one or both of the pairsof wheels configured as described could also operate effectively.Rather, the claimed invention includes all such modifications as maycome within the scope of the claims and equivalents thereto.

1-12. (canceled)
 13. A tilting wheeled vehicle, comprising: a frametiltable side-to-side within a tilting range of motion of the frame; aright wheel defining a first wheel plane that intersects the rightwheel; a left wheel defining a second wheel plane that intersects theleft wheel; a steering system including: a tilting linkage including anupper portion having right and left upper cross members operably securedto the frame at a shared upper pivot, and a lower portion having rightand left lower cross members operably secured to the frame at a sharedlower pivot; a right kingpin having the right wheel mounted thereto andpivotally secured to the right upper cross member and the right lowercross member of the tilting linkage at the first wheel plane to define afirst steering axis of the right wheel; a left kingpin operativelysecured to the left wheel mounted thereto and pivotally secured to theleft upper cross member and the left lower cross member of the tiltinglinkage at the second wheel plane to define a second steering axis ofthe left wheel; and a universal steering linkage secured to a steeringshaft along a frame plane that also includes the shared upper pivot andthe shared lower pivot, the universal steering linkage including a righttie rod and a left tie rod that are pivotable independent of each other,wherein the right tie rod is operably secured to the right kingpin, andthe left tie rod is operably secured to the left kingpin..